Answer: I'm not convinced you're dealing with aphids, but that's generally what fits the description you've given. Black bean aphids are larger than the green aphids we're accustomed to seeing in the garden. They do the same kind of damage, though, and multiply like wildfire. They can be gray or black and their legs are quite visible. While aphids don't actually chew holes in leaves, they do suck the juices out, which will make the leaves turn yellow, or become deformed, or just plain wilt. Try hosing them off with a strong stream of water, or use Insecticidal Soap to control them.
Q&A Library Searching Tips